$4.[0/1$ Points$]$ I LARCALC$1210\mathrm{.}1\mathrm{.}506.$XP$.1$

In mountainous areas, reception of radio and television is sometimes poor. Consider an idealized case where a hill is represented by the graph of the parabola $\backslash ($ y$=$x$-$x$^\{2\}\backslash ),$ a transmitter is located at the point $\backslash ((-5,3)\backslash ),$ and a receiver is located on the other side of the hill at the point $\backslash (\backslash$left$($x$\_\{0\},0\backslash$right$)\backslash ).$ What is the closest the receiver can be to the hill while still maintaining unobstructed reception? $($Round your answer to three decimal places.$)$

$0\mathrm{.}745$